764 research outputs found

    Testing the Bell Inequality at Experiments of High Energy Physics

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    Besides using the laser beam, it is very tempting to directly testify the Bell inequality at high energy experiments where the spin correlation is exactly what the original Bell inequality investigates. In this work, we follow the proposal raised in literature and use the successive decays J/ψγηcΛΛˉpπpˉπ+J/\psi\to\gamma\eta_c\to \Lambda\bar\Lambda\to p\pi^-\bar p\pi^+ to testify the Bell inequality. Our goal is twofold, namely, we first make a Monte-Carlo simulation of the processes based on the quantum field theory (QFT). Since the underlying theory is QFT, it implies that we pre-admit the validity of quantum picture. Even though the QFT is true, we need to find how big the database should be, so that we can clearly show deviations of the correlation from the Bell inequality determined by the local hidden variable theory. There have been some critiques on the proposed method, so in the second part, we suggest some improvements which may help to remedy the ambiguities indicated by the critiques. It may be realized at an updated facility of high energy physics, such as BES III.Comment: 16 pages, 5 figure

    Review: Towards the agroecological management of ruminants, pigs and poultry through the development of sustainable breeding programmes. II. Breeding strategies

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    Agroecology uses ecological processes and local resources rather than chemical inputs to develop productive and resilient livestock and crop production systems. In this context, breeding innovations are necessary to obtain animals that are both productive and adapted to a broad range of local contexts and diversity of systems. Breeding strategies to promote agroecological systems are similar for different animal species. However, current practices differ regarding the breeding of ruminants, pigs and poultry. Ruminant breeding is still an open system where farmers continue to choose their own breeds and strategies. Conversely, pig and poultry breeding is more or less the exclusive domain of international breeding companies which supply farmers with hybrid animals. Innovations in breeding strategies must therefore be adapted to the different species. In developed countries, reorienting current breeding programmes seems to be more effective than developing programmes dedicated to agroecological systems that will struggle to be really effective because of the small size of the populations currently concerned by such systems. Particular attention needs to be paid to determining the respective usefulness of cross-breeding v. straight breeding strategies of well-adapted local breeds. While cross-breeding may offer some immediate benefits in terms of improving certain traits that enable the animals to adapt well to local environmental conditions, it may be difficult to sustain these benefits in the longer term and could also induce an important loss of genetic diversity if the initial pure-bred populations are no longer produced. As well as supporting the value of within-breed diversity, we must preserve between-breed diversity in order to maintain numerous options for adaptation to a variety of production environments and contexts. This may involve specific public policies to maintain and characterize local breeds (in terms of both phenotypes and genotypes), which could be used more effectively if they benefited from the scientific and technical resources currently available for more common breeds. Last but not least, public policies need to enable improved information concerning the genetic resources and breeding tools available for the agroecological management of livestock production systems, and facilitate its assimilation by farmers and farm technicians

    High Yields of Shrimp Oil Rich in Omega-3 and Natural Astaxanthin from Shrimp Waste

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    A valued marine oil rich in omega-3 lipids and natural astaxanthin is obtained with remarkably high yield (up to 5 wt %) extending to pink shrimp waste (head and carapace) using the approach to extract fish oil from fish processing byproducts using d-limonene. Biobased limonene is an excellent solvent for both unsaturated lipids and astaxanthin-based carotenoids preventing oxidative degradation during the extraction cycle including solvent separation at 85 °C. Explaining the deep red color of the shrimp oil obtained, computational simulation suggests that d-limonene is also a good solvent for natural astaxanthin abundant in shrimp

    CP violation in J/ψΛΛˉJ/\psi \rightarrow \Lambda \bar \Lambda

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    We study CP violation in J/ψΛΛˉJ/\psi \rightarrow \Lambda \bar{\Lambda} decay. This decay provides a good place to look for CP violation. Some observables are very sensitive to the Λ\Lambda electric dipole moment dΛd_\Lambda and therefore can be used to improve the experimental upper bound on dΛd_\Lambda. CP violations in the lepton pair decays of J/ψJ/\psi and Υ\Upsilon are also discussed.Comment: 8 pages, RevTex, UM-P-92/113, OZ-92/3

    A century of poultry genetics

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    The 20th Century saw an astonishing advance in our understanding of genetics and the scientific basis of the genetic improvement of farm animals. The application of genetic principles to chickens in the 1950s and 1960s led to a rapid change in the productivity and efficiency of laying hens and broiler chickens, turkeys and ducks. Subsequently, the application of increasingly powerful computers and sophisticated mathematical algorithms has increased the range of traits that could be successfully incorporated into breeding programs. Random sample tests of the performance of laying hens enjoyed a period of popularity and more recently the few remaining tests included husbandry systems in addition to strain evaluation. Characterisation of avian blood groups has led to the identification of the B21 haplotype that confers resistance to Marek's disease and to selection for this locus in commercial lines. The decade following the millennium saw the publication of the genome sequence of the chicken and the identification of millions of single nucleotide polymorphisms that, coupled with technological advances, made the application of whole genome selection practical in poultry. In parallel, the molecular basis for some Mendelian traits described a century ago is now being deciphered. Similar technologies have been applied to study genetic diversity in chickens and have provided insights into the evolution and domestication of chicken breeds. Finally, in this review, the recent development of the European Poultry Genetics Symposia coordinated by Working Group 3 ‘Genetics and Breeding’ that was based on combining the British Poultry Breeders Round Table and AVIAGEN from West and Eastern Europe, is discusse

    Phenotypic characterisation and molecular polymorphism of indigenous poultry populations of the species Gallus gallus of Savannah and Forest ecotypes of Benin

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    The study of the phenotypic characterisation and molecular polymorphism of local chicken populations was carried out in Benin on 326 chickens of the Forest ecological area and 316 of the Savannah ecological area, all were 7 months old at least. The collection of blood for the molecular typing wasachieved on 121 indigenous chickens of which 60 from the Savannah ecological area and 61 from the Forest ecological area. The genotyping was carried out for 22 microsatellite loci. Weight and body measures of the Savannah chickens were significantly higher (P < 0.001) than those of the Forest chickens. In the Savannah ecological area, the most frequent plumage colours were the black (22.15%), the white (19.62%), the coppery black (7.59%) and the golden partridge (7.59%). In the Forest area, thefawn (15.34%), the black (10.43%), the white (6.8%), the silver white (6.8%) and the golden partridge (6.75%) were the dominant feather colours. Thus, phenotypic characterisation showed significant differences between Savannah and Forest local chickens. The FST calculated between the Savannah and Forest populations revealed a low genetic differentiation and the dendogram showed that Savannah and Forest chickens were quite intermingled. In conclusion, local populations from Savannah andForest area may be considered as ecotypes, but not as two distinct breeds

    Search for Direct CP Violation in Non-Leptonic Decays of Charged Ξ\Xi and Λ\Lambda Hyperons

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    A search for direct CP violation in the non-leptonic decays of hyperons has been performed. In comparing the product of the decay parameters, αΞαΛ\alpha_{\Xi}\alpha_{\Lambda}, in terms of an asymmetry parameter, AΞΛA_{\Xi\Lambda}, between hyperons and anti-hyperons in the charged ΞΛπ\Xi \to \Lambda \pi and Λpπ\Lambda \to p \pi decay sequence, we found no evidence of direct CP violations. The parameter AΞΛA_{\Xi\Lambda} was measured to be 0.012±0.0140.012 \pm 0.014.Comment: Submitted for publication; RevTex, 13 pages, 4 figure
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